Just peace of mind really. If the kawasaki engineers saw fit to spend the extra money for the stock sprockets to have it then there must be a reason. Kinda along the same lines as some aftermarket wheels come with no cush drive but the RCs I have on my ZX9 have a cush drive while Peerformance Machine wheels usually dont. I think that it will in time save a little shock to the drive train which means less wear and tear.gladding24 said:Floyd, I'm just curious, what's your hangup with the rubber damper? Are you worried about something happening without one on the CS sprocket?